This invention relates generally to the field of fiber optics. More particularly, this invention relates to high-resolution axial and radial distance alignment of an optical fiber element to another optical fiber element.
In the field of fiber optics, problems exist with the physical alignment of two optical elements. Prior solutions to aligning optical fiber and optical fiber arrays generally rely upon detection of a physical edge of a first fiber with a camera, force feedback, or linear encoding. These methods inherently require reliance on assumptions about the location of a second optical element, be it an optical fiber, waveguide, or other optical component relative to the edge of the first fiber that was detected. All final alignment of the axial distance and radial position is dependent upon the accuracy of these assumptions. These assumptions can result in uncertainty with respect to the final axial distance and radial alignment of the two optical elements. This uncertainty imposes limitations on these techniques.
The present invention relates generally to axial distance and radial distance alignment of an optical fiber element to another optical fiber element. These optical fiber elements can include, but are not limited to, optical fiber strands, optical fiber arrays, optical fiber cables, optical filters, optical amplifiers, optical waveguide devices, etc. Objects, advantages and features of the invention will become apparent to those skilled in the art upon consideration of the following detailed description of the invention.
In accordance with certain embodiments consistent with the present invention, fiber optic alignment methods and apparatus in accordance with the present invention first identify a target beam width incidence on an end of an optical element. The end of the optical element is placed into a beam of light at an axial location relative to the beam of light. The end of the optical element is subsequently moved transversally (perpendicular) to the beam of light until a position of maximum optical power, as measured through the optical element, is identified. A beam width of the beam of light is measured at that axial location. The movement and measurement sequence is repeated at multiple axial locations relative to the beam of light. Linear regression, or an equivalent approach is used, to predict an axial location relative to the beam of light with the target beam width. The end of the optical element is then moved to the axial location with the target beam width.
In accordance with certain embodiments consistent with the present invention, a method of fiber optic alignment, wherein a target beam width of a beam of light is defined along a path of the beam of light on a first end of a fiber optic element, and wherein the fiber optic element is situated with light incident upon the first end of the fiber optic element, involves measuring a beam width at multiple locations axially relative to said beam of light; calculating a location axially relative to said beam of light wherein said beam of light has a beam width that equals said target beam width of said beam of light; and moving said fiber optic element to said location. This method and other methods disclosed herein can be carried out using instructions stored on an electronic storage medium that are executed on a programmed processor.
In accordance with certain embodiments consistent with the present invention, an apparatus for fiber optic alignment, consistent with certain embodiments of the present invention has a control processor. A first end of a fiber optic element is moved within a beam of light responsive to the control processor. Optical power transmitted through the fiber optic element is measured at a second end of the fiber optic element and the measurement is provided to the control processor. The control processor carries out instructions that measure a beam width at multiple locations axially relative to the beam of light; calculate a location axially relative to the beam of light wherein the beam of light has a beam width that equals the target beam width of the beam of light; and move the fiber optic element to the location.
Many variations, equivalents and permutations of these illustrative exemplary embodiments of the invention will occur to those skilled in the art upon consideration of the description that follows. The particular examples above should not be considered to define the scope of the invention.